末屑

末 = 一 + 木 : Mnemonic symbol: a Jehovah’s Witness, because they think the end (末) is near.

Mahatma Gandhi (m) set up a giant flute (一) on a Christmas tree (木), trying to raise awareness for the Roof of the World in the observatory's bathroom (o4). He chose the flute and the tree as symbols for the sky and nature, but as Jehovah’s Witness (末) enters, she thinks it's the sky that has fallen down on our heads, and the end (末) of days is ultimately here.

屑 = 尸 + 肖 : Marie Curie (xi) and the little prince (肖) are frequently visiting a ghost (尸) in the elevator's bathroom (e4). The ghost is feeding on their dandruff (屑), therefore it's a win-win situation for all of them, but secretly they feel it beneath their dignity (不屑).